Heart makes artificial ray swim

Inspired by a ray, scientists have created a small robot that swims by means of genetically manipulated heart cells.

Biological component: Rat embryo heart cells Size: 1.5 cm

Aray was an obvious choice, when scientists from Harvard University aimed to create a swimming biobot. The natural ray is an elegant swimmer, and its simple shape is reasonably easy to imitate. The three main components that scientists used to make a robotic version of a ray is gold, silicone rubber, and heart cells from a rat. The gold makes up the skeleton, whereas two layers of silicone are the robot’s body, which is lined with several layers of heart cells. The 1.5 cm robot includes a total of about 200,000 heart cells, which function as its muscles, and to provide them with the right shape, scientists placed a template of a special protein along the robot’s sides, on which they grew the cells.

Before the cells were placed on the ray, they were supplied with an extra gene which makes them contract when light of a specific wavelength is shone on them. In this way, scientists can control the robot, as it moves about a culture dish at a speed of a modest 2 mm/s.